Process for preparing an alternating copolymer of an alpha-olefin and a conjugated diene

ABSTRACT

ALTERNATING COPOLYMERS OF AN A-OLEFIN AND A C5-C12 CONJUGATED DIENE ARE FORMED BY REACTION IN THE PRESENCE OF A CATALYST COMPRISING AN ORGANOALUMINUM COMPOUND HAVING THE FORMULA ALR3 WHEREIN R REPRESENTS A C1-C12 HYDROCARBON RADICAL SELECTED FROM THE GROUP CONSISTING OF ALKYL, CYCLOALKYL, ARYL AND ARALKYL RADICALS AND AN ORGANOTITANIUM COMPOUND HAVING   X-TI-OOC-R   STRUCTURE IN THE MOLECULE WHEREIN R IS AS DEFINED ABOVE AND X IS HALOGEN.

June 5, 1973 KIYQSHIGE HAYASHI ET AL 3,737,417

PROCESS FOR PREPARING AN ALTERNATING COPOLYMER OF AN OLEFIN AND A CONJUGATED DIENE Filed May 5, 1971 12 Sheets-Sheet 1 4000'3000 '20'00' "500' lo'oo' 760 cm June 5, 1973 KIYOSHIGE HAYASHI ET AL 3,737,417

PROCESS FOR PREPARING AN ALTERNATING COPOLYMER OF AN OLEFIN AND A CONJUGATED DIENE Filed May .5, 1971 12 Sheets-Sheet 8 7 11 n 7 3 N 2 3 F 0 m N 1 N on, T C H EUD .I D Hm ml mm AR W YW. J AU W H 0 N EA m m l N wn wmm K 0 June 5, 1973 12 Sheets-Sheet. 5

Filed May 5, 1971 m sq June 1973 KIYOSHIGE HAYASHI ETA!- 3,737,417

PROCESS FOR PREPARING AN ALTERNATING COPOLYMER OF AN OLEFIN AND A CONJUGATED DIENE' Filed May 5, 1971 12 Sheets-Sheet 4 June 1973 KIYOSHIGE HAYASHI ET AL 3,737,417

PROCESS FOR PREPARING AN ALTERNATING COPOLYMER OF AN OLEFIN AND A CONJUGATED DIENE 12 Sheets-Sheet 5 Filed May 5, 1971 OON . coo.

m Qt

June 1973 KIYOSHIGE HAYASHI ET AL 3,737,417

PROCESS FOR PREPARING AN ALTERNATING COPOLYMER OF AN OLEFIN AND A CONJUGATED DIENE Filed May 5, 1971 12 Sheets-Sheet 6 June 1973 KIYOSHIGE HAYASHI ET 3,737,417

PROCESS FOR PREPARING AN ALTERNATING COPOLYMER OF AN OLEFIN AND A CONJUGATED DIENE Filed May 5, 1971 12 Sheets-Sheet 7 June 5, 1973 KIYQSHIGE s -u ET AL 3,737,417

PROCESS FOR PREPARING AN ALTERNATING COPOLYMER OF AN OLEFIN AND A CONJUGATED DIENE Filed May 5, 1971 12 Sheets-Sheet 8 June 5, 1973 KIYOSHIGE HAYASHI ET AL 3,737,417

PROCESS FOR PREPARING AN ALTERNATING COPOLYMER OF AN OLEFIN AND A CONJUGATED DIENE Filed May 5, 1971 12 Sheets-Sheet 9 June 5, 1973 KIYOSHIGE HAYASHI ETAL PROCESS FOR PREPARING AN ALTERNATING COPOLYMER OF AN OLEFIN AND A CONJUGATED DIENE Filed May 5, 1971 12 Sheets-Sheet 10 June 5, 1973 KIYOSHIGE HAYASHl ET AL 3,737,417

- PROCESS FOR PREPARING AN ALTERNATING COPOLYMER OF AN OLEFIN AND A CONJUGATED DIENE Filed May 5, 1971 12 Sheets-Sheet 11 crrr QOOO m m June 5, 1973 KlYQsHlGE HAYA5H| ET AL 3,737,417

PROCESS FOR PREPARING AN ALTERNATING COPOLYMER OF AN OLEFIN AND A CONJUGATED DIENE Filed May 5, 1971 12 Sheets-Sheet 18 United States Patent Oflice Patented June 5, 1973 ABSTRACT OF THE DISCLOSURE Alternating copolymers of an a-olefin and a C -C, conjugated diene are formed by reaction in the presence of a catalyst comprising an organoaluminum compound having the formula AlR wherein R represents a C C hydrocarbon radical selected from the group consisting of alkyl, cycloalkyl, aryl and aralkyl radicals and an organotitanium compound having XTiOQIR structure in the molecule wherein R is as defined above and X is halogen.

RELATED APPLICATION This application is related to application Ser. No. 120,405, filed Mar. 23, 1971, wherein alternating copolymers of butadiene and an a-olefin, and a process for preparing the same, are described.

BACKGROUND OF THE INVENTION (1) Field of the invention The present invention relates to a process for preparing an alternating copolymer of an u-olefin having the general formula of CHgCHR wherein R represents a C C 4 hydrocarbon radical selected from the group consisting of alkyl, cycloalkyl, aryl and aralkyl radicals and a C -C conjugated diene and a novel alternating copolymer of a C -C conjugated diene and said a-olefin,

(2) Description of the prior art In order to obtain new and useful synthetic elastomers, many attempts have been made to produce alternating copolymer of a conjugated diene and an oc-Olefitl. However, the copolymerization reaction is very difiicult and, in general, it is not easy to produce even a random copolymer of conjugated diene and a-olefin by an ionic catalyst.

For example, Belgian Pat. 546,150 reports a process for preparing an amorphous copolymer of butadiene and an a-olefin having more than 3 carbon atoms by using a catalyst system of trialkylaluminum and titanium tetrachloride at 50 C. The copolymer was determined to be amorphous from their X-ray measurements. The chemical configuration of the copolymer is not stereospecific. On the other hand, for example, an alternating copolymer of butadiene and propylene is also shown to be amorphous from its X-ray spectrum at room temperature, but it is a stereospecific copolymer and therefore it can crystallize on stretching or on cooling.

British Pat. 1,026,615 claims a process for preparing a random copolymer of butadiene and propylene by forming a catalyst system of trialkylaluminum and titanium tetrachloride in the presence of propylene, and then adding butadiene to the catalyst system. According to the patent, the propylene content of the copolymer was much higher than that of the copolymer prepared by the catalyst system formed in the absence of propylene. The patent also describes that analysis has shown that the copolymer obtained is a random copolymer and not block copolymer, but there are shown no experimental results which support the assumption.

British Pat. 1,108,630 shows a process for preparing a rubbery random copolymer of butadiene and propylene of high molecular Weight with high content of propylene by using a three component catalyst system consisting of trialkylaluminum, iodine and a compound having the general formula of TiBr,,Cl,, wherein n is zero or an integer of 1 to 4. The microstructure of butadiene unit and the content of propylene unit in the copolymer are shown in the patent. But there are shown no experimental results which support the assumption that the copolymer should be a random copolymer of butadiene and propylene. A random copolymer of butadiene and propylene was also prepared by using a catalyst system consisting of triethylaluminum, titanium tetrachloride and polypropylene oxide. Polypropylene oxide was used as a randomizer and a copolymer of butadiene and propylene prepared by the catalyst system of triethylaluminum and titanium tetrachloride was shown to be block type from the results of oxidative decomposition reaction of the copolymer (Paper presented at 2nd Symposium on Polymer Synthesis, Tokyo. Oct. 5, 1968, The Society of Polymer Science, Japan).

At any rate, all of the methods described above relate to the methods for preparing a nonstereospecific or atactic copolymer. On the other hand, an alternating copolymer is stereospecific one and therefore these methods are not pertinent to the process of this invention.

Recently, Furukawa et al. reported a process for preparing an alternating copolymer of butadiene and an a-olefin by using vanadyl (V) chloride-diethylaluminum monochloride-triethylaluminum catalyst system (22nd Annual Meeting of Japan Chemical Society, Tokyo, Mar. 31, 1969; I. Polymer Sci., B7, 671 (1969)).

The methods for preparing an alternating copolymer of butadiene and an u-olefin by using an organoaluminum compound-vanadium (IV) chloride or vanadium (V) oxychloride-organic peroxide or chromium (VI) oxychloride catalyst system (Ger. Offen. 1,963,780), an organoaluminum compound-a vanadium compound having no vanadium-halogen linkage-a halogen compound catalyst system (Ger. Ofien. 1,964,706; I. Polymer Science, B7, 613 (1969)) and an organoaluminum compound-a vanadium compound having vanadium-halogen linkage-a compound having MOR (M is an atom whose electronegativity is less than 2.2 and R is a hydrocarbon radical) linkage catalyst system (Ger. Oifen. 2,020,168; Neth. appl. 7,006,067) were all proposed by us previously.

In short, the catalyst systems for alternating copolymerization described above employ an organoaluminum compound and a vanadium compound as indispensable elements of the catalyst systems. The microstructure of butadiene units in the alternating copolymer of butadiene and an oz-Olefil'l prepared by these catalyst systems was almost all trans-1,4-configuration, occasionally involving minor amounts of 1,2-configuration.

On the other hand, most recently, we proposed the process for preparing an alternating copolymer of butadiene and an a-olefin by using the three component catalyst system of an organoaluminum compound, titanium tetrahalide and a carbonyl group containing compound (Ger. Offen. 2,023,405, Neth. appl. 7,006,877). The alternating copolymer prepared by this catalyst system contains considerable amounts of cis-1,4-configuration butadiene unit, occasionally involving minor amounts of cis-l,2-configuration and moreover molecular weight of the alternating copolymer is remarkably higher than that of the one prepared by the organoaluminum-vanadium compound type catalyst system described above.

As far as the inventors know, with the exception of the methods described above, there is found to be no prior art in connection with an alternating copolymer of a conjugated diene and an u-olefin nor of a process for the preparation thereof.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a process for preparing an alternating copolymer of a C -C conjugated diene and an a-olefin having a high molecular weight in a good yield.

It is a further object of this invention to provide a catalyst system giving high molecular weight alternating copolymer of a C C conjugated diene and an a-olefin in a good yield.

It is a still further object of this invention to provide an alternating copolymer of a C -C conjugated diene and an a-olefin having the general formula of CH =CHR wherein R represents a C -C hydrocarbon radical selected from the group consisting of alkyl, cycloalkyl, aryl and aralkyl radicals.

DESCRIPTION OF THE DRAWINGS FIG. 1 shows the infra-red spectrum of the typical example of alternating copolymer of isoprene and propylene prepared by the method of this invention; FIG. 2 shows the nuclear magnetic resonance spectrum of the copolymer; FIG. 3 shows the infra-red spectrum of the typical example of alternating copolymer of isoprene and butene-l prepared by the method of this invention; FIG. 4 shows the nuclear magnetic resonance spectrum of the copolymer; FIG. 5 shows the infra-red spectrum of the typical example of alternating copolymer of isoprene and pentene-l prepared by the method of this invention; FIG. 6 shows the nuclear magnetic resonance spectrum of the copolymer; FIG. 7 shows the infra-red spectrum of the typical example of alternating copolymer of isoprene and hexene-l prepared by the method of this invention; FIG. 8 shows the nuclear magnetic resonance spectrum of the copolymer; FIG. 9 shows infra-red spectrum of the typical example of alternating copolymer of pentadiene-1,3- and propylene; FIG. 10 shows the nuclear magnetic resonance spectrum of the copolymer; FIG. 11 shows the infra-red spectrum of the alternating copolymer of isoprene and propylene prepared by the catalyst system of triisobutylaluminum, vanadium (V) oxychloride and partial hydrolysis product of aluminum triisopropoxide at 40 C.; and FIG. 12 shows the nuclear magnetic resonance spectrum of the copolymer.

DETAILED DESCRIPTION OF THE INVENTION In accordance with this invention, we have found that a high molecular weight alternating copolymer of a C -C conjugated diene and an a-olefin can be produced in a good yield by using a catalyst system comprising of the first component of an organoaluminum compound having the general formula of AlR wherein R represents a hydrocarbon radical selected from the group consisting of a C -C preferably C -C and more preferably C -C alkyl, cycloalkyl, aryl and aralkyl radicals and the second component of an organotitanium compound having 0 XTiOi JR (R is the same one as described above and X is halogen) structure in the molecule or the catalyst system composed of the first component of an organoaluminum compound having the general formula of AlR wherein R is as defined above, the second component of an organotitanium compound having (R and X are as described above) structure in the molecule and the third component of halogen, a halogen compound or a mixture thereof.

The alternating copolymers of this invention are rubberlike in character and can be used as polymeric plasticizers, in adhesives and can be vulcanized with sulfur or a sulfur compound to produce vulcanized elastomers.

The organoaluminum compounds which form the first component of the catalyst system of this invention are defined by the formula AlR wherein R is a hydrocarbon radical selected from the group consisting of a C -C preferably C -C and more preferably C -C alkyl, cycloalkyl, aryl and aralkyl radicals. Mixtures of these organoaluminum compounds may also be employed. Specific examples of compounds represented by the formula include trimethylaluminum, triethylalu-minum, tri-npropylaluminum, triisopropylaluminum, tri-n-butylaluminum, triisobutylaluminum, triphentylaluminum, trihexylaluminum, tricyclohexylaluminum, trioctylaluminum, triphenylaluminum, tri-p-tolylaluminum, tribenzylaluminum, ethyldiphenylaluminum, ethyl di-p-tolylaluminum, ethyl dibenzylaluminum, diethylphenylaluminum, diethyl ptolylaluminum, diethyl benzylaluminum and the like. Mixtures of these compounds may also be employed. Of these, it is usually preferred to employ trialkylaluminum compounds.

The organotitanium compounds having vention, by no means limiting, are compounds shown by the general formulae of O X'Ii(OR)2(Of R), etc. and mixtures thereof.

A mixture of an organotitanium compound having TiOf JR (R is as defined above) structure and having no TiX linkage in the molecule and halogen, a halogen compound or a mixture thereof can be used as the second component of the catalyst of this invention, provided that said organotitanium compound can react with halogen, said halogen compound or the mixture thereof to produce an organotitanium compound having XTiodR structure, in situ. Examples of such TiOi JR structure containing compounds, by no means limiting, are the compounds shown by the general formulae of i i Ti OCR 4,0 Ti OCR 7:]2, Ti(OR)a(Of 7R),

I ll

etc. Examples of R radicals employed in the above organotitanium compounds are, by no means limiting, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, pentyl, hexyl, cyclohexyl, octyl, phenyl, p-tolyl, benzyl and other radicals.

The halogen compounds which form the third component of the catalyst system of this invention and also used as the halogen source for transforming the compounds having Tiof m structure to the second component of the catalyst system, by no means limiting, are the ones showing Lewis acid property such as compounds of the general formulae VX (X is halogen hereinafter the same), VOX WX MoX CrO X ZrX FeX BX PX SnX SbX AlOX, AlX CuX, MnX MgX ZnX HgX BiX NiX TiX etc.; Lewis base complex compounds of the above-mentioned halogen compounds showing Lewis acid property such as compounds of the general formulae A1X -O(C H NiX 'Py (Py represents pyridine), HgX -Py, etc.; organoaluminum compounds having AlX linkage such as compounds of Al(OR),,X (n is a number from 1 to 2 and R is as defined above), AlR,,X (n is a number from 1 to 2 and R is as defined above), etc.; organotransition metal compounds having transition metal -X linkage such as compounds of the general formulae (n is a number from 1 to 2), Ti(OR). X (n is a number from 1 to 3), Zr(OR) X Zr(OR) X, OV(C5H7O2) X (n is a number from 1 to 2), V(C H ,X.,, (n is a number from 1 to 2), V(C H X, OV(C H )X (C H IrX etc.; acid halide; compounds having the general formula of halogenated alkane compounds such as tert-butyl halide, secbutyl halide, carbon tetrahalide, etc. and a mixture thereof.

The components of the catalyst system are normally employed in catalytic quantities. In the preferred embodiment the molar ratio of organoaluminum compound which forms the first component of the catalyst system of the present invention to organotitanium compound which forms the second component of the catalyst system should be in the range of 200 to 1 (200 Al/Ti 1), the optimum ratios will be found between 100 and 2 (100 Al/Ti 2).

In the preferred embodiment, the atomic ratio of titanium atom in the catalyst system of the present invention to halogen atom in the catalyst system should be in the range of 0.01 to 20 (0.01 Ti/X 20), the optimum ratios vw'll be found between 0.00. and (0.02 Ti/ X 10).

The a-olefin used in this invention is one having the general formula:

, CH =CHR wherein R is a hydrocarbon radical selected from the group consisting of a C -C preferably C -C and more preferably C -C al-kyl, cycloalkyl, aryl and aralkyl radical. Specific examples of compounds represented by the formula include propylene, butene-l, pentene-l, 4methylpentene-l, hexene-l, 4-methyl-hexene-1, S-methyl-hexene- 1, heptene-l, S-methyl-heptene-l, octene-l, decene-l, vinylcyclohexane, 4 methyl-l-vinylcyclohexane, styrene and the like. Mixtures of these ot-olefin monomers may also be employed.

The conjugated dienes to be used in the present invention have from 5 to 12 carbon atoms, and typical examples are pentadiene-1,3, hexadiene-1,3, isoprene, Z-ethyl butadiene, 2-propy1 butadiene, 2-isopropyl butadiene, 2,3-dimethyl butadiene, phenyl butadiene, etc. Among them, isoprene and pentadiene-l,3 are preferable. A mixture of them may also be employed.

The molar ratio of conjugated diene to u-olefin in the initial monomer composition is not critical, but is usually within the range of 10/1 to l/ (10/1 diene/a-olefin 1/100), preferably be 10/2 to 1/50 (10/2 diene/uolefin 1/50). It is noteworthy that, for example, when copolymerization reaction proceeds 50% by using a monomer mixture having the initial monomer composition of 1:50, the molar ratio of unreacted conjugated diene to unreacted m-olefin at this stage should be 1:99.

The manner for preparing the catalyst system of this invention has not been found to be critical. The organoaluminum compound which forms the first component of the catalyst system and the organotitanium compound which forms the second component of the catalyst system or the organoaluminum compound, the organotitanium compound and the halogen or halogen compound which forms the third component of the catalyst system of the present invention can be mixed per se or they can be mixed in the presence of an organic solvent. If a solvent is to be employed, the aromatic solvent suchpas benzene, toluene, xylene, etc.; the aliphatic hydrocarbon, e.g. propane, butane, pentane, hexane, heptane, cyclohexane, etc.; the halogenated hydrocarbon solvent such as trihaloethane, methylene halide, tetrahaloethylene, etc. are usually preferred.

In general, the organoaluminum compound which forms the first component of the catalyst system and the organotitanium compound which forms the second component of the catalyst system may be mixed at a temperature in the tables given hereinafter. The halogen +100" C., and preferably from -78 C. to +50 C. This temperature is shown as catalyst preparation temperature in the tables given hereinafter. The halogen or halogen compound which forms the third component of the catalyst system may be mixed with the other one or two components of the catalyst system of this invention at a temperature within a very wide range from 100 C. to +100 C., and preferably from 78" C. to +50 C.

The polymerization reaction may be carried out at a temperature within a range from 100 C. to +100 C., and preferably from 78" C. to +50 C.

The practice of this copolymerization is usually carried out in the presence of an organic solvent or diluent. However, this does not mean that this invention cannot be practiced in the form of bulk polymerization, i.e. without the use of solvent. If it is desired to use a solvent, the aromatic solvent such as benzene, toluene, xylene, etc.; the aliphatic hydrocarbon, e.g. propane, butane, pentane, hexane, heptane, cyclohexane, etc.; halogenated hydrocarbon solvent such as trihaloethane, methylene halide, tetrahaloethylene and the like may also be employed.

At the completion of the copolymerization reaction, the product may be precipitated and deashed by using a methanolhydrochloric acid mixture. The precipitated product may be further washed with methanol for several times and dried under vacuum.

As shown in Examples 1, 4 and Experiments 1 and 2 of Example 5 in detail, the products obtained in these examples were determined, through many facts, as the alternating copolymers of isoprene with propylene, hexene-l, pentene-l and butene-l respectively. Also, as shown in Examples 6 and 8 in detail, the products obtained in these examples were determined, through many facts, as the alternating copolymers of pentadiene-l,3 with propylene and hexene-l respectively.

The invention will be illustrated with reference to the following examples.

7 EXAMPLE 1 The usual, dry, air-free technique was employed and 8.0 milliliters toluene and varying amounts of organotitanium compound were put into 25 milliliter glass bottles at 25 C. Then, the bottles were held in a constant temmer over a wide range of initial monomer composition.

(6) The copolymerization reaction gives 1:1 copolymer independently of polymerization time.

In FIG. 2, 8.321 peak may be ascribed to methyl group of cis-1,4-structure of isoprene unit and 8.421- peak perature bath showing predetermined temperature (it 5 may 1 g z to the l of methyl grotfips of corresponds to catalyst preparation temperature) and if; l l 0 g g mm of t e varying amounts of organoaluminum compound solution p0 Y f It 18 Cone u t h Structure in toluene (1 molar solution) were put into the bottles fz lsoprene mm of the copolymer 1S nly c1s-l,4-strucrespectively. Thereafter, the bottles were held in a low 1 temperature bath at -78 C. and a mixture of 2.0 milli- 0 In contrast Wlth h spectrum liters liquid propylene and 2.0 milliliters liquid isoprene Sharp Peak appear? at 909 The band 15 a sslgned was put into the each bottle also employing the usual, to 1,2-structure of isoprene unit of the alternating codry, air-free technique. Then, the bottles were sealed and p y The Strength of 5 ad 8 50' cm. band allowed to copolymerize at predetermined temperature assigned to L4-slfllctul'e 0f l p In FIG. 1 1s and for predetermined time. The results were summarized stronger than that of the one in FIG. 11. In FIG. 12, in Table 1. in contrast with the spectrum in FIG. 2, it is found that TABLE 1 Alternating copoly- Polymerization mer of isoprene and Catalysts conditions propylene Catalyst Organopreparation Intrinsic Exp. aluminum temperature Temp. Time Yield viscosity N0. compound Mmole Organotitanium compound Mmole 0.) C.) (1112) (g.) [1 (dl./g.)

ll 1 A1(iBu) 1.0 TiOl3(OOCH3) 0- -40 -40 18 0. 30

ll 2 Al(i-Bu); 1.0 TiCl [OOOH(CH3) CHa]: 0. --40 --40 18 0.13

3 Ala-Bu); 1.0 TiCl (OgO H 0.5 -40 -40 18 1.40

4 Al(iBu) 1.0 ()[TiClz(OCC H5)]2 0-25 -40 40 18 0.43

5 AlEt 0.3 Ticl oi iorm 0.1 78 20 145 0.97 0. 40

1 Microstructure of isoprene unit of the alternating copolymer is as follows: 1,2: 0%; 1,4: 90%; 3,4: 10%.

2 Measured in chloroform at C.

The following results support the conclusion that the copolymer is an alternating copolymer of isoprene and propylene.

(1) In the infra-red spectrum of the copolymer (FIG. 1), there can be seen no peak near 909 cm.- which corresponds to the band assigned to 1,2-structure of polyisoprene. The 890 cm. band is assigned to 3,4-structure of isoprene unit and the broad band at 850* cm.- is assigned to 1,4-structure of isoprene unit of the copolymer. Therefore, it is concluded that microstructure of isoprene unit of the copolymer is substantially composed of 3,4- and 1,4-structures.

In FIG. 2, the triplet at 4.8T is ascribed to the proton directly attached to the double bond of 1,4-structure isoprene unit and the weak doublet at 5.31- is ascribed to isopropenyl methylene group of 3,4-isoprene unit of the copolymer. Measuring the ratio of peak area of the triplet at 4.81- to half of that of the peak at 5.37, the ratio of 1,4-structure to 3,4-structure is found to be 94/6.

(3) Copolymer composition were determined by measuring the ratio of peak area of the triplet at 4.87 and half of the peak area of the doublet at 5.37- to one third of the peak area of the doublet at 9.21- assigned to methyl group of propylene unit of the copolymer. It is found that the composition of the copolymer according to the NMR analysis substantially agrees well with the calculated value for the 1:1 copolymer of isoprene and propylene.

(4) 1,4-polyisoprene shows a peak at 7.957 which is assigned to methylene group of the polymer. 0n the other hand, there can be seen substantially no peak at 7.957 in the NMR spectrum of the copolymer obtained in this example. This means that there are substantially no 1,4-isoprene repeating units in the copolymer. 8.11 peak may be assigned to methylene group of 1,4-isoprene unit of the alternating copolymer.

(5) The copolymerization reaction gives 1:1 copoly- Percent 1,4-structure 88 1,2-structure 5 3,4-structure 7 The special features of the structure of the alternating copolymer of isoprene and propylene prepared by the method of this invention are as follows:

(a) Microstructure of isoprene unit of the alternating copolymer is composed of large amounts of 1,4-structure and minor amounts of 3,4-structure.

(b) The most part of the 1,4-structure units of isoprene is cis-l,4-structure.

(0) Existence of ll-structure unit of isoprene can scarcely be detected by its infra-red spectrum.

EXAMPLE 2 The usual, dry, air-free technique was employed and 8.0 milliliters toluene, varying amounts of organo-titanium com-pound and varying amounts of halogen compound were put into 25 milliliter glass bottles at 25 C. Then, the bottles were heldin a constant temperature bath showing predetermined temperature (it corresponds to catalyst preparation temperature given in Table 2) and varying amounts of triisobutylaluminum solution in toluene (1 molar solution) were put into the bottles respectively. Thereafter, the bottles were held in a low temperature at 78 C. and a mixture of 2.0 milliliters liquid propylene and 2.0 milliliters liquid isoprene was 3.0 kg. alternating copolymer prepared under the same polymerization conditions as Exp. No. 4 was vulcanized as follows:

100 parts of copolymer,

put 1nto each bottle also employing the usual, dry, air- 50 parts of oil furnace black (HAFJ free technique. Then, the bottles were sealed and allowed 5 parts of Zinc oxide to copolymerize at predetermined temperature and for 1 t f l h redetermined time The results were summarized in par 5 o ,g 2 1 part of stearic acid,

' 1 part of phenyl-fi-naphthylamine and 1 part of benzothiazyl disulfide TABLE 2 Yield of Catalysts 1 Polymerization alternating H 1 Catalyst conditions eopolymer or;

a 0 911 01' 1'6 813 1011 S 6 Exp Ala-Bu); halog en t emgerature Temp. Time 1 gi ogg i e r ie o. (mmole) Organotitanium compound Mmole compound Mmole 0.) (hr.) (g.)

1 1. 0 CI)' 0. 2 CeHaCOCl 0. 1 -40 -40 18 0. 48

TiCl3(OCOCH 2 1.0 H 0.2 AlCla-OEt 0.1 40 --40 1a 0. 33

T1C12[0CCH(CH3)CH3]7 1. 0 Same as above 0. 2 tert-BuCl 0. 2 -40 -40 18 0. .do 0.2 I: 0.1 -40 -40 18 0.16

H 0. SnCli 0.1 -40 18 0.62 OlTiCMOCCqHOh 6 1.0 H 0.1 SnCh 0.2 -40 -40 18 0.02

O[Ti(OCCHs)3]2 1.0 Same as above 0.1 AlEtCla 0.2 -40 -40 18 0.04

0.1 FeCh 0.1 40 40 18 0.02

H 0.2 SbCls 0.2 -40 -40 18 0.02 Ti(Oi-Pr) (OCCHs)2 1.0 Same as above 0.2 VOCI; 0.1 -40 -40 18 1.57

0.3 g 0.1 Br: 0.1 -78 20 94 0.34

0[Ti(OCCHa)s]2 EXAMPLE 3 The usual, dry, air-free technique was employed and 7.0 milliliters toluene and 0.21 millimole organo-titanium compound were put into 25 milliliter glass bottles at 25 C. Then, the bottles were held in a constant temperature bath showing predetermined temperature (it corresponds to catalyst preparation temperature given in Table 3) and 0.50 milliliter triisobutylaluminum solution in toluene (1 molar solution) were put into the bottles respectively. Thereafter, the bottles were held in a low temperature bath at 78 C. and a mixture of 2.0 milliliters liquid propylene and 2.0 milliliters liquid isoprene was put into each bottle also employing the usual, dry, air-free technique. Then, the bottles were sealed and allowed to copolymerize at predetermined temperature for predeterwere mixed on a roller and vulcanized at 140 C. for 30 minutes. The product obtained by the vulcanization had the following values:

The usual, dry, air-free technique was employed and 7 .0 milliliters toluene, 0.1 millimole ohioicmll and 0.3 milliliter ethylaluminum dichloride solution in toluene (1 molar solution) were put successively into a 25 milliliter glass bottle at 20 C. Then, the bottle was mmed time. The results were summarized in Table 3. held in a low temperature bath at -78 C. and 10 milli- TABLE 3 Catalysts Alternating copolymer Polymerization of isoprene and 0 Catalyst conditions propylene & preparation Exp. Al(l-Bu)a TiCMO CaHs) temperature Tempera- Time Yield Intrinsic vis- No. (mmole) (mmole) 0.) time 0.) (hr (g.) cosity [1 -ls) 1 Measured in chloroform at 80 C.

l 1 liter triisobutylaluminum solution in toluene '(1 molar solution) and a mixture of 3.0 milliliters liquid hexeue-l and 2.0 milliliters liquid isoprene were put successively into the bottle also employing the usual, dry, air-free technique. Thereafter, the bottle was sealed an allowed to copolymerize at 30 C. for 16 hours. The yield of the alternating copolymer of isoprene and hexene-l was 0.23 g. The microstructure of isoprene unit of the copolymer was as follows: 1,2: 1,4: 92%; 3,4: 8%.

The following results support the conclusion that the copolymer is an alternating copolymer of isoprene and hexene-l.

(1) In the infra-red spectrum of the copolymer (FIG. 7), there can be seen no peak near 909 cmr' Therefore, it is concluded that microstructure of isoprene unit of the alternating copolymer is substantially composed of 3,4- and 1,4-structures.

(2) In FIG. 8, measuring the ratio of peak area of the triplet at 4.81- to half of that of the weak peak at .31", the ratio of 1,4-structure to 3,4-structure is found to be 90/ 10.

(3) It is found that the composition of the copolymer according to the NMR analysis substantially agrees well with the calculated value for the 1:1 copolymer of isoprene and hexene-l. The method for measuring the copolymer compositions was applied as was used in the case of alternating copolymer of isoprene and butene-l.

(4) In FIG. 8, there can be seen substantially no peak at 7.951- corresponding to 1,4-isoprene repeating unit. This means that 1,4-isoprene repeating unit does not appear in the copolymer.

(5) The copolymerization reaction gives 1:1 copolymer over a wide range of initial monomer composition.

(6) The copolymerization reaction gives 1:1 copolymer independently of polymerization time.

In FIG. 8, as in the case of alternating copolymer of isoprene and propylene, by comparing peak area of 8.351- peak and that of 8.40-r shoulder, it is found that the structure of isoprene unit of the copolymer is mainly cis-1,4- structure.

The alternating copolymer of isoprene and hexene-l is also found to be a new material.

EXAMPLE 5 The usual, dry, air-free technique was employed and 7.0 milliliters toluene, 0.2 millimole organotitanium compound and 0.5 millimole halogen compound were put successively into 25 milliliter glass bottes at 20 C. Then, the bottles were held in a constant temperature bath showing predetermined temperature (it corresponds to catalyst preparation temperature given in Table 4) and 2.0 milliliters organoaluminum compound solution in toluene (1 molar solution) was put into each bottle. Thereafter, the bottles were held in a low temperature bath at --78 C. and 2.0 milliliters liquid isoprene and 3.0 milliliters liquid tit-Olefin were put successively into the bottles also employing the usual, dry, air-free technique. Then, the bottles were sealed and allowed to copolymerize at 40 C. for 28.5 hours. The results were summarized in Table 4.

The following results support the conclusion that the copolymer obtained in Experiment 2 of Example 5 is an alternating copolymer of isoprene and butene-l.

(1) In the infra-red spectrum of the copolymer (FIG. 3), there can be seen no peak near 909 cm. which corresponds to the band assigned to 1,2-structure of polyisoprene. The 890 cm.- and 845 cm." bands are assigned to 3,4- and 1,4-structure of isoprene unit of the copolymer, respectively. Therefore, it is concluded that microstructure of isoprene unit of the copolymer is substantially composed of 3,4- and 1,4-structures.

(2) In FIG. 4, the triplet at 4.81- is ascribed to the proton directly attached to 1,4-isoprene double bond and the weak peak at 5.37 is ascribed to isopropenyl methylene group of 3,4-isoprene unit of the copolymer. Measuring the ratio of peak area of the triplet at 4.81 to half of that of the peak at 5.37, the ratio of 1,4-structure to 3,4-structure is found to be 93/7.

(3) Copolymer composition were determined as follows:

if A is peak area of the triplet at 4.87, B is peak area of the peak at 5.37 and C is peak area of the all peaks appeared in the region from 7.51- tO 9-57',

the molar ratio of isoprene to butene-l in the copolymer can be shown by the following equation;

It is found that the composition of the copolymer according to the NMR analysis substantially agrees well with the calculated value for the 1:1 copolymer of isoprene and butene-l.

(4) In FIG. 4, there can be seen substantially no peak at 7 .95 1' corresponding to 1,4-isoprene repeating unit. This means that 1,4-isoprene repeating unit does not appear in the copolymer.

(5) The copolymerization reaction gives 1:1 copolymer over a wide range of initial monomer composition.

(6) The copolymerization reaction gives 1:1 copolymer independently of polymerization time.

In FIG. 4, as in the case of alternating copolymer of isoprene and propylene, by comparing peak area of 8.327 peak and that of 8.401- peak, it is found that the structure of isoprene unit of the copolymer is mainly cis-1,4-structure. As in the case of the alternating copolymer of iso prene and propylene, the alternating copolymer of isoprene and butene-l of the present invention is a new material.

The following results support the conclusion that the copolymer obtained in Experiment 1 of Example 5 is an alternating copolymer of isoprene and pentene-l.

(1) In the infra-red spectrum of the copolymer (FIG. 5), there can be seen no peak near 909 cmr- Therefore, it is concluded that microstructure of isoprene unit of TAB LE 4 Catal sts y Catalyst Organo- Organopreparation Example aluminum titanium Halogen temperature number compound Mmole compound Mmole compound Mmole C.)

1 Al(i-Bu)3 2. 0 (H) 0. 2 AlCla-OEtz 0. 5 -4O O[Ti(0 C Et)a]z 2 AlEta 2. 0 Same as above. 0. 2 AlEtClz 0. 5 -78 Alternating copolymer of isoprene and a-olefin Monomers Polymerization conditions Microstructure of isoprene urnt Liquid Example Liquid isoprene Temp. Time Yield 1, 2 1, 4 3, 4 number aolefin Ml. m1 0.) (hr.) (g.) (percent) (percent) (percent) 1 Pentene-l. 3. 0 2. 0 28. 5 0. 99 0 94 6 2 Butane-L 3. 0 2. 0 40 28. 5 0. 19 0 93 7 13 the copolymer is substantially composed of 3,4- and 1,4- structures.

(2) In FIG. 6, measuring the ratio of peak area of the triplet at 4.81- to half of that of the weak peak at 5.31, the ratio of 1,4-structure to 3,4-structure is found to be if A is peak area of the triplet at 4.71- and C is peak area of the all peaks appeared in the region from 7-57 to 9.51,

the molar ratio of pentadiene to propylene in the copoly- 94/6 mer can be shown by the following equation;

(3) I is found that the composition of the copolymer according to the NMR analysis substantially agrees well pentadlene 3A with the calculated value for the 1:1 copolymer of isopropylene (C3A)/6 C'3A prene and pentene-l. The method for measuring the co- Polymer Q was apPhed as was s the case It is found that the composition of the copolymer accordof alternatmg copolymer of soprene and ing to the NMR analysis substantially agrees well with (4) In the.re can be substamlauy.no e the calculated value for the 1:1 copolymer of pentaat 7.85acorrespond ng to 1,4-1soprene repeating unit. diene 1,3 andpropy1ene This metafiis thatllA-isoprene repeating unit does not ap.- (4) The cqpolymerizafiopllteacfion gives 1:1 co-p913 Eg ig z iii reaction c 01 mer over a Wide range of imtial monomer composition.

mer over a Wi de iange of initial mono n ier compo i tioii (5) 1 6 f ymfenzitwn ffiaqnon-glves 1:1 copolymer in epen ent y 0 p0 ymerlzation time.

g f i i t i 001,013" ('6) Although the greater part of the 1,4-structure units mer in epen en y o- 110 ymerlz 1011 i of pentadiene-1,3 1S trans-1,4, crystallization sensltlve g ii i' 313253 3 3515;335: 531 izgg g ggg bands of trans-1,4-polypentadiene at 781, 866, 939, 1025 cm.- scarcely be found in FIG. 9. In the NMR spec- Peak f that of 3 Peak 1t founfi thait the trum of amorphous polypropylene, a doublet ascribing to ture of Somme mm of the copolymer mamly methyl group appears at 9.117 and 9.217. 0n the other structure 1 f 1 hand, in FIG. 10, the doublet shifts to 9.047 and 9.15r.

altgmatmg copo ymer and pentene' 18 This means that the doublet is ascribed to methyl group aso Dun to be a new mate of propylene unit of alternating copolymer of penta- EXAMPLE 6 diene-1,3 and propylene.

. The alternating copolymer of pentadiene-1,3 and pro- The usual, dry, air-free technique was employed and 2.0 milliliters toluene and varying amounts of organoggif a i fg f ggif gf g ttSl;Igrgan0a1ununum titanium compound were put into 25 milliliter glass boti c0 olisider d t b a tles at 25 0. Then, the bottles Were held in a low temnew $3 3 g Ym 3 c 8 6 perature bath at 78 C. (it corresponds to catalyst preparation temperature in Table 5) and 0.6 milliliter g zg j g gi ggg 21; grg gg z g pigggg gg a; or anoaluminum com ound solution in toluene 1 molar sol ution) and a mixti ire of 0.4 milliliter liquid propylprocess of thls mventlon 15 as follows: ene, 0.6 milliliter liquid cis-pentadiene-1,3 and 1.0 milli- (a) Microstructure of pentadiene-1,3 unit of the alternatliter toluene were put successively into the bottles also ing copolymer is 1,4structure. employing the usual, dry,air-free technique. Thereafter, 40 (b) The greater part of the 1,4-structure units of pentathe bottles were sealed and allowed to copolymerize at diene-l,3 is trans-1,4-structure. --40 C. for 110 hours. The results were summarized in (c) Existence of 1,2-structure unit of pentadiene-1,3 can Table 5. scarcely be detected by its infra-red spectrum.

TABLE 5 Alternating copolymer of pentadiene and a-olefin Polymerization Microstructure of Catalysts Cataliyst conditions pentadiene unit prepara on 0 t Example oa li ir iinum Organotitanium tii r e Temp. -Time Yield Cis-1,4 Trans-1,4 1,2 number compound Mmol compound Mmol 0.) 0.) (hr.) (g.) (percent) (percent) (percent) 1 Al(i-Bu)z 0.6 0 0.2 78 40 110 0.02 8 92 TiCl2(0C CH(CHa)OHs)a 2 Ala-Bu); 0.6 O 0.2 78 -40 110 0.23 9 91 0 T101 00 CBH5 8 AlEt, 0. 6 Same as above- 0. 2 78 40 110 0. 15 10 90 0 4. Ala-Bu): 0.6 0 0.1 -78 40 110 0.18

0(Ti01i0zbctHt):

The following results support the conclusion that the EXAMPLE 7 copolymer is an alternating copolymer of pentadiene- The usual, dry, air-free technique was employed and 1,3 and propylene. 2.0 milliliters toluene, 0.2 millimole organotitanium (1) In the infra-red spectrum of the pentadiene-propylcompound and 0.1 millimole halogen compound were put ene copolymer (FIG. 9), it is found that microstructure successively into 25 milliliter glass bottles at 25 C. Then, of pentadiene unit of the copolymer is substantially 1,4- the bottles were left alone at 25 C. for 10 minutes. structure. Thereafter, the bottles were held in a low temperature (2) In the NMR spectrume of the copolymer (FIG. bath at -78 C. (it corresponds to catalyst preparation 10), the triplet at 4.71 is ascribed to the protons directly temperature) and 0.6 millimole organoaluminum comattached to the double bond of pentadiene unit showing pound solution in toluene (1 molar solution) and a mix- 1,4-structure. ture of 0.4 milliliter liquid propylene, 0.6 milliliter liquid (3) Copolymer compositions were determined as cis-pentadiene-1,3 and 1.0 milliliter toluene were put follows:

successively into the bottles also employing the usual.

for '110 hours. The yield of the alternating copolymer of cis-pentadiene-1,'3 and hexene-l soluble in diethyl ether and insoluble in MEK was 0.01 g.

15 dry, air-free technique. Then, the bottles were sealed and allowed to copolymerize at 40 C. for 110 hours. The results were summarized in Table 6.

TABLE 6 Catalysts Catalyst Organopreparation Ex. aluminum Halogen temperature No. compound Mmol organotitanium compound Mmol compound C.)

1 Al(i-Bu)3 0. 6 u 0. 2 AlBra 0. 1 78 TiCl2(O C OH(CHa) CH3) 2 2 Al(i-Bu)3 0. 6 Same as above 0. 2 0511 0 Cl 0. 1 --78 3 AlEta 0. 6 H 0. 2 SbCl O. 1 -78 TiChO 0 CH3 4 Al(i-Bu)a 0. 6 H 0. 2 SnClr 0. 1 -78 O[l'.i(O C 0113):;12

5 Al(i-Bu) O. 6 fl) 0. 2 AlCk-OEtz 0. 1 -78 Ti(0 CH(CH3)CH3)2(OCCH3)2 Polymerization Alternating copolymer of pentadiene and conditions a =olefin Mierostructure of pentadiene Temperature Cis-1,4 Trans-1,4 1, 2 Example number C.) Time (hr.) Yield (g.) (percent) (percent) (percent EXAMPLE 8 EXAMPLE 10 The usual, dry, airfree technique was employed and 2.0 milliliters toluene and 0.2 millimole O t TiClaO CaHS were put into a 25 milliliter glass bottle at 25 C. Then, the bottle was held in a low temperature bath at -78 C. and 0.6 milliliter triisobutyl aluminum solution in toluene (1 molar solution) and a mixture of 0.6 milliliter liquid cis-pentadiene-1,3 0.4 milliliter liquid hexene-l and 1.0 milliliter toluene were put successively into the bottle also employing the usual, dry, air-free technique. Thereafter, the bottle was sealed and allowed to copolymerize at C. for 110 hours. The copolymer thus obtained was determined as an alternating copolymer of cis-pentadiene-1,3 and hexene-l by many facts, such as IR spectrum and NMR spectrum thereof. The yield of the alternating copolymer of cis-pentadiene-1,3 and hexene-l soluble in diethyl ether and insoluble in MEK was 0.02 g.

EXAMPLE 9 The usual, dry, air-free technique was employed and 2.0 milliliters toluene, 0.2 millimole and 0.1 millimole stannic chloride were put successively into a 25 milliliter glass bottle at 25 C. Then. the bottle was left alone at 25 C. for 10 minutes. Thereafter, the bottle was held in a low temperature bath at -78 C. and 0.6 milliliter triisobutylaluminum solution in toluene (1 molar solution) and a mixture of 0.6 milliliter liquid cis-pentadiene-1,3, 0.7 milliliter liquid hexene-l and 1.0 milliliter toluene were put successively into the bottle also employing the usual, dry, air-free technique. Then, the bottle was sealed and allowed to copolymerize at 40 C.

The usual, dry, air-free technique was employed and 7.0 milliliters toluene, 0.2 millim-ole and 0.2 millimole AlCl -OEt Were put successively into a 25 milliliter glass bottle at 20 C. Then, the bottle was held in a low temperature bath at 78 C. and 1.0 milliliter triisobutylaluminum solution in toluene (1 molar solution) and a mixture of 1.0 milliliter liquid cis-pentadiene-1,3 and 1.0 milliliter propylene were put successively into the bottle also employing the usual, dry, airfree technique. Thereafter, the bottle was sealed and allowed to copolymerize at 40 C. for 24 hours. The yield of the alternating copolymer was 0.20 g. The microstructure of pentadiene unit of the copolymer is as follows: Cis-1,4: 20%; 1,4: 80%.

What is claimed is:

1. A process for preparing a 1:1 copolymer of a C C conjugated diene and an a-olefin having alternating said conjugated diene and said a-olefin units, said a-olefin having the general formula of CH =CHR wherein R represents a C -C hydrocarbon radical selected from the group consisting of an alkyl, a cycloalkyl, an aryl and an aralkyl radical, which comprises contacting said conjugated diene and said a-olefin in liquid phase with a catalyst composed of (A) an organoaluminum compound having the general formula of MR, wherein R is as deiined above and (B) an organotitanium compound havmg (R is as defined above and X is halogen) structure in the molecule.

2. A process as claimed in claim 1 wherein a halogen, a halogen compound or a mixture thereof is further included as a component of the catalyst.

3. A process as claimed in claim 1 wherein the atomic ratio of aluminum atom contained in the organoalumi- 

